In modern motor vehicles, in particular electric vehicles, large electrical currents are necessary for the operation of the vehicles. These large currents are transported in the cable harness of the vehicle through appropriately dimensioned lines or conductors or cables between the battery and the electrical load, e.g. an electric motor. Lines or conductors or cables with large cross sections are used to keep the electric losses low caused by the resistance of the lines. The use of lightweight aluminum lines additionally increases the cross sections of the lines. The currents are controlled by semiconductor components located in control units (ECU). The term control unit is used in automotive engineering generally as collective term for electrical units distributed in housings. The semiconductor components are usually arranged on printed circuit boards, on which there are also other electronic components. To connect the printed circuit boards and the components arranged thereon with the on-board system, usually contact elements are provided on the printed circuit board. These can be connected to mating contacts, which are arranged at the ends of the cables of the cable harness. Within vehicles the installation space is naturally tight. Therefore, the contacts in general are attached to the edges of the printed circuit board to allow for a flat design of the control unit. This situation requires that the plug contacts need to be designed such that they are accessible on the housing wall for the contact parts of the cable harness. The contact elements have a cover of plastic material for protection. This socket at the control unit is generally referred to as “header”. The contact parts of the cable ends of the cable harness are integrated in a connector housing. This type of electrically contacting of cable harness and control unit has been proven in automotive engineering for many years. However, there are limits if the currents to be transmitted are getting into orders of magnitude of Amperes, as occur with electric vehicles by default. The transfer resistance of these contact systems is significant; they consume electrical energy that they convert into heat. Contact elements for large current densities have large dimensions with relatively low resistance, since the resistance of the current path need not get too large. Large contact elements require large plugs and corresponding sockets. This increases the required space for the control units. Another problem is in the control units themselves. A not to be underestimated thermal load is formed by the large currents flowing through the electrical components. This heat needs to be dissipated through thermally good conductive elements, which are mounted to the heat-generating elements, to the housing and to the environment. In addition, passive and/or active ventilation systems may need to be provided for guiding air into the housing for cooling and discharging the heated air. This need for cooling makes the control units bigger, heavier, and more expensive.